Copyright 2013 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

PROVIDENCE, Rhode Island (AP) -- Relatives of the dead suspect in the Boston Marathon bombing will claim his body now that his wife has agreed to release it, an uncle said as officials in both Washington and Russia deepened their investigations into him and his ties.

The body of Tamerlan Tsarnaev, 26, has been at the medical examiner's office in Massachusetts since he died after a gunfight with authorities more than a week ago.

Tamerlan and brother Dzhokhar Tsarnaev, both Russian natives who lived for several years in the U.S., are accused of using a weapon of mass destruction during the April 15 marathon. Three people were killed and more than 260 injured when two bombs exploded near the finish line.

Amato DeLuca, the attorney for Tamerlan's widow, Katherine Russell, said Tuesday that his client had just learned that the medical examiner was ready to release Tsarnaev's body and that she wants it released to his side of the family.

Police said Tsarnaev ran out of ammunition before 19-year-old Dzhokhar dragged his body under a vehicle while fleeing the scene. His cause of death has been determined but will not be made public until his remains are claimed.

"Of course, family members will take possession of the body," uncle Ruslan Tsarni of Maryland told The Associated Press on Tuesday night. "We'll do it. We will do it. A family is a family."

He would not elaborate. The brothers' parents are still in Russia, but other relatives on their side of the family in the U.S., including Tsarni.

Dzhokhar Tsarnaev lies in a prison hospital after being wounded in the shootout with police as he and his brother made their getaway attempt. He is charged with using a weapon of mass destruction to kill, a crime that carries a potential death sentence.

Russian agents placed the older suspect under surveillance during a six-month visit to southern Russia last year, then scrambled to find him when he suddenly disappeared after police killed a Canadian jihadist, a security official told the AP.

U.S. law enforcement officials have been trying to determine whether Tamerlan Tsarnaev was indoctrinated or trained by militants during his visit to Dagestan, a Caspian Sea province that has become the center of a simmering Islamic insurgency.

The security official with the Anti-Extremism Center, a federal agency under Russia's Interior Ministry, confirmed the Russians shared their concerns. He said Russian agents were watching Tsarnaev, and that they searched for him when he disappeared two days after the July 2012 death of the Canadian man, who had joined the Islamic insurgency in the region. The official spoke only on condition of anonymity because he was not authorized to speak to the news media.

Security officials suspected ties between Tsarnaev and the Canadian -- an ethnic Russian named William Plotnikov -- according to the Novaya Gazeta newspaper, which is known for its independence and investigative reporting and cited an unnamed official with the Anti-Extremism Center, which tracks militants. The newspaper said the men had social networking ties that brought Tsarnaev to the attention of Russian security services for the first time in late 2010.

President Barack Obama said Tuesday at a news conference that the U.S. counterterrorism bureaucracy "did what it was supposed to be doing" before the Boston Marathon bombing as his top intelligence official began a review into whether sensitive information was adequately shared and whether the U.S. government could have disrupted the attack.

In Rhode Island, DeLuca said Tamerlan Tsarnaev's widow met with law enforcement "for many hours over the past week" and will continue cooperating. FBI agents on Monday visited her parents' North Kingstown, Rhode Island, home, where she has been staying, and carried away several bags.

Copyright 2013 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.